Cubic Metres Crushed Concrete To Tonnes Converter
Convert crushed concrete volume into tonnes for recycled sub-base, temporary hardstanding, trench backfill and bulk delivery planning.
Crushed Concrete Inputs
Weight And Delivery
Crushed concrete grading, fines content, moisture and compaction change bulk density. Check supplier data before final ordering.
What This Converter Does
This page estimates tonnes of crushed concrete from cubic metres. Crushed concrete is often used as recycled aggregate for sub-base, temporary hardstanding, backfill and firming up access routes. It may be sold loose by the tonne, in bulk bags or as part of a haulage quote. The calculator shows base weight, adjusted order weight, bag count, lorry loads and cost.
Recycled crushed concrete can vary more than freshly quarried aggregate. A load may contain different proportions of concrete, mortar, brick, fines and larger pieces depending on the source and processing. That variation affects density and how well the material compacts.
Formula Used
Base tonnes = cubic metres x density. Adjusted tonnes = base tonnes x compaction factor. Order tonnes = adjusted tonnes x allowance. Bags and lorry loads are rounded up from the final order weight.
If the volume is a finished compacted volume, the selected density and compaction factor should reflect that finished condition. If it is a loose stockpile volume, use a loose density and treat compaction separately.
Density Guide
| Material condition | Planning density | Use note |
|---|---|---|
| Light recycled fill | 1.50 t/m3 | May include more voids or mixed material. |
| Typical crushed concrete | 1.65 t/m3 | Useful first estimate for loose material. |
| Compacted recycled sub-base | 1.85 t/m3 | Use where a finished compacted layer is being estimated. |
| Certified Type 1 recycled | supplier data | Use project or supplier density where available. |
Worked Examples
Three Cubic Metres
3 m3 of typical crushed concrete at 1.65 t/m3 is 4.95 tonnes before allowance. With 10% extra, the order is 5.45 tonnes.
Compacted Layer
3 m3 at 1.85 t/m3 gives 5.55 tonnes before allowance. This can better reflect a compacted sub-base assumption.
Bulk Bags
If each bag is 0.85 tonnes, a 5.45 tonne order rounds to seven bags. Loose tipped delivery may be easier at that quantity.
Quality And Suitability Checks
Crushed concrete should be suitable for the job. Check grading, fines content, certification, contamination limits and whether the material is accepted by the project specification. For drainage layers, too many fines can reduce permeability. For sub-base, a well-graded compactable material may be required. For sensitive sites, recycled material may need documentation.
Do not use a weight converter to approve the material itself. The calculator tells you how much to order, not whether the recycled aggregate meets the engineering requirement.
Layer Planning For Sub-Base Work
For patios, paths, sheds and light vehicle areas, the important measurement is normally the finished compacted layer. If the drawing calls for a 100 mm sub-base over 24 m2, the finished volume is 2.40 m3 before any allowance. A loose delivery will settle as it is spread and compacted, so a loose pile volume may not match the finished layer volume. The compaction factor field lets you make that adjustment visible instead of hiding it in a single rounded figure.
Depth should be measured after excavation levels are set. If the ground has soft spots, ruts or old service trenches, the real fill volume can be higher than the neat drawing volume. Add a larger allowance where the formation is uneven, where edges need trimming by hand, or where a small surplus is better than stopping work short. For jobs with formal specifications, follow the project requirement for layer thickness, compaction method and testing.
Delivery, Tickets And Waste Notes
Loose tipped crushed concrete is usually more practical than many small bags once the order reaches several tonnes, but it needs a suitable place for the lorry to tip. Check overhead cables, narrow entrances, weak covers, soft verges and shared access before booking. If the site cannot take a tipped load, bulk bags may be easier to place but can cost more per tonne.
Ask the supplier whether the product is weighed, estimated from loader bucket volume, or sold as nominal bag weight. A weighbridge ticket gives a clearer mass than a visual estimate. Keep delivery records where recycled material provenance matters. If the job produces surplus, store it on a clean surface so soil and green waste do not mix in. Contaminated leftovers may be harder to reuse on a later job.
Ordering And Site Notes
- Ask whether the quoted density is loose or compacted.
- Check for visible contaminants before spreading.
- Use a higher allowance for uneven excavations and hand trimming.
- Plan delivery access; recycled aggregate is heavy.
- Compact in layers where the specification calls for compaction.
FAQs
How many tonnes are in one cubic metre of crushed concrete?
A typical loose planning value is about 1.65 tonnes per cubic metre. Compacted material can be nearer 1.85 tonnes per cubic metre.
Is crushed concrete the same as MOT Type 1?
No. Some recycled products may be sold to a Type 1 grading, but generic crushed concrete is not automatically the same.
Should I add a waste allowance?
Yes for many site jobs, especially where levels are uneven or trimming is needed.
Can I use it for drainage?
Only if the grading and fines content are suitable. Check the product specification.
Does this include compaction?
The compaction factor lets you adjust weight, but it does not replace a proper compaction specification.
Sources
- Waste and Resources Action Programme. (2024). Recycled aggregates guidance. WRAP. https://wrap.org.uk/
- National Highways. (2024). Specification for Highway Works, Series 800. National Highways. https://www.standardsforhighways.co.uk/
- British Standards Institution. (2013). BS EN 1097-3: Determination of loose bulk density and voids. BSI. https://knowledge.bsigroup.com/
- National Institute of Standards and Technology. (2008). Guide for the Use of the International System of Units (SI), Special Publication 811. NIST. https://www.nist.gov/pml/special-publication-811